Devices for rotatably supporting articles have heretofore been proposed which comprise a base plate formed with an annular recessed portion and steel balls arranged on the recessed portion at a specified pitch so that the article can be rotatably supported by the steel balls, as disclosed in British Pat. No. 1,231,388 and Swiss Pat. No. 159,371. However, these devices, in which the article and the base plate are united, have the problem of being unsuited to universal use.
Accordingly the present applicant has already proposed a rotating apparatus which is universally usable and shown in FIG. 13. The apparatus is disclosed in detail in the specification of U.S. Pat. No. 4,433,954.
With reference to FIG. 13, the rotating apparatus comprises an under ring 81 serving as an under member, a plurality of roller bearings 8 mounted on the under ring 81 in vertical and horizontal positions, an upper ring 80 supported by the bearings and serving as an upper member, and a retaining member 82 for holding the two rings together. The apparatus is annular in its entirety and can be transported by rolling. Moreover, when a pallet is placed on the upper ring 80, a heavy article such as a drum can be rotatably supported by the apparatus. However, the apparatus, which includes the plurality of roller bearings, has a problem in respect of cost because the bearings and the retaining member 82 must be fixed to the rings by an expensive manual procedure.